Experimental observation of adiabatic compression and expansion of soliton pulses over long fiber paths

1989 ◽  
Vol 14 (14) ◽  
pp. 751 ◽  
Author(s):  
K. Smith ◽  
L. F. Mollenauer
Keyword(s):  
Experimental Observation ◽  
Adiabatic Compression ◽  
Compression And Expansion

scholarly journals Modelling the Energy Spectra of Radio Relics

Galaxies ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 111
Author(s):  
Denis Wittor ◽  
Matthias Hoeft ◽  
Marcus Brüggen
Keyword(s):  
Tracer Particle ◽  
Galaxy Cluster ◽  
Cosmic Ray ◽  
Radio Spectrum ◽  
Adiabatic Compression ◽  
Energy Spectra ◽  
Similar Amount ◽  
Inverse Compton Scattering ◽  
Tracer Particles ◽  
Compression And Expansion

Radio relics are diffuse synchrotron sources that illuminate shock waves in the intracluster medium. In recent years, radio telescopes have provided detailed observations about relics. Consequently, cosmological simulations of radio relics need to provide a similar amount of detail. In this methodological work, we include information on adiabatic compression and expansion, which have been neglected in the past in the modelling of relics. In a cosmological simulation of a merging galaxy cluster, we follow the energy spectra of shock accelerated cosmic-ray electrons using Lagrangian tracer particles. On board of each tracer particle, we compute the temporal evolution of the energy spectrum under the influence of synchrotron radiation, inverse Compton scattering, and adiabatic compression and expansion. Exploratory tests show that the total radio power and, hence, the integrated radio spectrum are not sensitive to the adiabatic processes. This is attributed to small changes in the compression ratio over time.

The Brayton Cycle Using Real Air and Polytropic Component Efficiencies

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
W. H. Heiser ◽  
T. Huxley ◽  
J. W. Bucey
Keyword(s):  
Constant Pressure ◽  
Adiabatic Compression ◽  
Design Parameters ◽  
Working Fluid ◽  
High Fidelity ◽  
Brayton Cycle ◽  
Closed Cycle ◽  
Perfect Gas ◽  
Power Cycle ◽  
Compression And Expansion

This paper presents the results of a fundamental, comprehensive, and rigorous analytical and computational examination of the performance of the Brayton propulsion and power cycle employing real air as the working fluid. This approach capitalizes on the benefits inherent in closed cycle thermodynamic reasoning and the behavior of the thermally perfect gas to facilitate analysis. The analysis uses a high fidelity correlation to represent the specific heat at constant pressure of air as a function of temperature and the polytropic efficiency to evaluate the overall efficiency of the adiabatic compression and expansion processes. The analytical results are algebraic, transparent, and easily manipulated, and the computational results present a useful guidance for designers and users. The operating range of design parameters considered covers any current and foreseeable application. The results include some important comparisons with more simplified conventional analyses.

Adiabatic compression and expansion of polystyrene

2007 ◽  
Vol 3 (8) ◽  
pp. 351-354 ◽  
Author(s):  
H. L. Toor ◽  
S. D. Eagleton
Keyword(s):  
Adiabatic Compression ◽  
Compression And Expansion

The Effect of Nonlinear Amplitude Growth on the Speech Perception Benefits Provided by a Single-Sided Vocoder

2019 ◽  
Vol 62 (3) ◽  
pp. 745-757 ◽  
Author(s):  
Jessica M. Wess ◽  
Joshua G. W. Bernstein
Keyword(s):  
Transfer Functions ◽  
Spatial Configuration ◽  
Free Field ◽  
Spatial Separation ◽  
Compression And Expansion ◽  
Interaural Difference ◽  
Interaural Differences ◽  
Single Sided Deafness ◽  
Perceptual Separation ◽  
Loudness Growth

PurposeFor listeners with single-sided deafness, a cochlear implant (CI) can improve speech understanding by giving the listener access to the ear with the better target-to-masker ratio (TMR; head shadow) or by providing interaural difference cues to facilitate the perceptual separation of concurrent talkers (squelch). CI simulations presented to listeners with normal hearing examined how these benefits could be affected by interaural differences in loudness growth in a speech-on-speech masking task.MethodExperiment 1 examined a target–masker spatial configuration where the vocoded ear had a poorer TMR than the nonvocoded ear. Experiment 2 examined the reverse configuration. Generic head-related transfer functions simulated free-field listening. Compression or expansion was applied independently to each vocoder channel (power-law exponents: 0.25, 0.5, 1, 1.5, or 2).ResultsCompression reduced the benefit provided by the vocoder ear in both experiments. There was some evidence that expansion increased squelch in Experiment 1 but reduced the benefit in Experiment 2 where the vocoder ear provided a combination of head-shadow and squelch benefits.ConclusionsThe effects of compression and expansion are interpreted in terms of envelope distortion and changes in the vocoded-ear TMR (for head shadow) or changes in perceived target–masker spatial separation (for squelch). The compression parameter is a candidate for clinical optimization to improve single-sided deafness CI outcomes.

Experimental observation of a doubly percolating system

1992 ◽  
Vol 2 (4) ◽  
pp. 365-369 ◽  
Author(s):  
Pablo Jensen ◽  
Patrice Melinon ◽  
Alain Hoareau ◽  
Jian Xiong Hu ◽  
Michel Treilleux ◽  
...  
Keyword(s):  
Experimental Observation
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